Numerical Simulation of Cutting Stress Deformation in Tungsten Carbide Turning Tools

2016 ◽  
Vol 836 ◽  
pp. 203-207
Author(s):  
Pei Hsing Huang ◽  
Jian Rong Chen ◽  
Hong Zhong Lu
Keyword(s):  
Thermal Deformation ◽  
Coupling Effect ◽  
Cutting Speed ◽  
Mechanical Coupling ◽  
Machining Errors ◽  
Steady State Temperature ◽  
Steel Analysis ◽  
Aisi 1045 ◽  
Tool Cutting

With the aim of enhancing the precision and quality of turning processes, this study investigated cutting stress and thermal deformation induced by friction between the tool and chip of a Wolfram carbide (WC) tool cutting AISI-1045 carbon steel. Analysis of cutting stress and thermal deformation using COMSOL Multiphysics software is useful for evaluating the compensation for machining errors and reducing tool wear. Three cutting loads were adopted for the simulation of the thermal conduction, and changes in temperature and the stress field. Simulation results show that thermal deformation in the tool tip is proportional to cutting speed and time. As long as the temperature of the tool remains below the quasi-steady-state temperature, the amount of deformation does not change significantly. An understanding of the thermo-mechanical coupling effect during turning can help to improve the accuracy of compensation for thermal deformation in turning tools.

scholarly journals Thermal network model and experimental validation for a motorized spindle including thermal–mechanical coupling effect

2021 ◽  
Author(s):  
Changjiang Zhou ◽  
Zefeng Qu ◽  
Bo Hu ◽  
Shengbo Li
Keyword(s):  
Network Model ◽  
Temperature Rise ◽  
Thermal Deformation ◽  
Coupling Effect ◽  
Dynamic Performance ◽  
Experimental Results ◽  
Motorized Spindle ◽  
Mechanical Coupling ◽  
Thermal Network ◽  
Proposed Model

Abstract Thermal deformation caused by temperature rise have an influence on the dynamic performance of a motorized spindle. In turn, the change in the dynamic performance will affect the temperature rise and thermal deformation of the system. However, the latter was rarely focused on in the previous literature. Therefore, a thermal network model of motorized spindle is enhanced by considering the thermal–mechanical coupling effect. Then, an iterative method is presented to solve the coupled equations, and a temperature test rig of the motorized spindle is set up to verify the proposed model. The relative error between the predicted and experimental results at two test points decreases by 9.56% and 3.44% after considering the thermal–mechanical coupling effect. The comparison with the experimental results shows that the proposed model with thermal–mechanical coupling effect can obtain a more accurate temperature field than the previous model.

Research on Cutting Residual Stresses Based on Thermo-Mechanical Coupling

2009 ◽  
Vol 628-629 ◽  
pp. 651-656
Author(s):  
Ying Qiang Xu ◽  
S.J. Li ◽  
T. Zhang ◽  
X.H. Yang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Cutting Speed ◽  
Element Model ◽  
Stress Generation ◽  
Workpiece Surface ◽  
Mechanical Coupling ◽  
Basic Parameters

Mathematical models of basic parameters, force and thermal parameters of cutting were obtained by applying the thermo-elastic-plastic theory and the heat-balance theory, according to the principle of residual stress generation in cutting process. Based on the 2D finite element model of chip molding with separation surface, the direct way was applied in thermo-mechanical coupling, and residual stress of cutting GH4169 were simulated and analyzed by finite element. The results showed that the residual stresses are changed from tensile to compressive with the development of depth away from the workpiece surface. Also its values are changed according to a certain rule as varying the cutting speed. These provide a foundation for the control of cutting quality of workpiece.

scholarly journals Modeling of Thermo-Chemo-Mechanical Properties of Anode Mixture during the Baking Process

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4320
Author(s):  
Bowen Chen ◽  
Hicham Chaouki ◽  
Donald Picard ◽  
Julien Lauzon-Gauthier ◽  
Houshang Alamdari ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Coupling Effect ◽  
Mechanical Parameters ◽  
Exponential Factor ◽  
Mechanical Coupling ◽  
Baking Process ◽  
Efficient Control ◽  
Carbon Anodes ◽  
Primary Aluminium

In the Hall–Héroult process, prebaked carbon anodes are utilized to produce primary aluminium. The quality of the anode plays a crucial role in the efficiency of electrowinning primary aluminium. In the production of anodes, the anode baking is considered as the stage most frequently causing anode problems. During the baking process, the anode undergoes complex physicochemical transformations. Moreover, the anode at a lower position, imposed by loading pressures from upper anodes, will creep during this process. Thus, the production of high-quality anodes demands efficient control of their baking process. This paper aims to investigate the thermo-chemo-mechanical properties of the anode paste mixture at high temperatures. These properties include kinetic parameters of pitch pyrolysis such as the activation energy and the pre-exponential factor, the thermal expansion coefficient (TEC) and relevant mechanical parameters related to the elastic, the viscoelastic and the viscoplastic behaviours of the anode. For this purpose, experiments consisting of the thermogravimetric analysis, the dilatometry and the creep test were carried out. Based on the obtained results, the forementioned parameters were identified. Relevant mechanical parameters were expressed as a function of a new variable, called the shrinking index, which is related to the volatile released in open and closed pores of the anode. This variable would be used to highlight the chemo-mechanical coupling effect of the anode mixture. New insights into the phenomena such as the expansion due to the increase of the pore pressure and the chemical shrinkage of the anode during the baking process were also gained in this work. These investigations pave the way for modeling the thermo-chemo-poromechanical behaviour of the anode during the baking process.

scholarly journals Analyzing the Effects of the Kinematic System on the Quality of Holes Drilled in 42CrMo4 + QT Steel

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4046
Author(s):  
Mateusz Bronis ◽  
Edward Miko ◽  
Lukasz Nowakowski
Keyword(s):  
Cutting Speed ◽  
Hole Drilling ◽  
Internal Cooling ◽  
Hole Quality ◽  
The Third ◽  
Kinematic System ◽  
Turning Center ◽  
Dimensional Errors ◽  
The Relationship

This article discusses the relationship between the kinematic system used in drilling and the quality of through-holes. The drilling was done on a CTX Alpha 500 universal turning center using a TiAlN-coated 6.0 mm drill bit with internal cooling, mounted in a driven tool holder. The holes were cut in cylindrical 42CrMo4 + QT steel samples measuring 30 mm in diameter and 30 mm in length. Three types of hole-drilling kinematic systems were considered. The first consisted of a fixed workpiece and a tool performing rotary (primary) and linear motions. In the second system, the workpiece rotated (primary motion) while the tool moved linearly. In the third system, the workpiece and the tool rotated in opposite directions; the tool also moved linearly. The analysis was carried out for four output parameters characterizing the hole quality (i.e., cylindricity, straightness, roundness, and diameter errors). The experiment was designed using the Taguchi approach (orthogonal array). ANOVA multi-factor statistical analysis was used to determine the influence of the input parameters (cutting speed, feed per revolution and type of kinematic system) on the geometrical and dimensional errors of the hole. From the analysis, it is evident that the kinematic system had a significant effect on the hole roundness error.

High-Speed End Milling Using a Feedforward Control Architecture

1996 ◽  
Vol 118 (2) ◽  
pp. 178-187 ◽  
Author(s):  
E. D. Tung ◽  
M. Tomizuka ◽  
Y. Urushisaki
Keyword(s):  
High Speed ◽  
Feedforward Control ◽  
End Milling ◽  
Phase Error ◽  
Cutting Speed ◽  
Frequency Domain Analysis ◽  
Maximum Speed ◽  
Drive Control ◽  
Machining Errors ◽  
Feedforward Controller

Experiments are performed for end milling aluminum at 15,000 RPM spindle speed (1,508 m/min cutting speed) and up to 3 m/min table feedrate using an experimental machine tool control system. A digital feedforward controller for feed drive control incorporates the Zero Phase Error Tracking Controller (ZPETC) and feedforward friction compensation. The controller achieves near-perfect (±3 μm) tracking over a 26 mm trajectory with a maximum speed of 2 m/min. The maximum contouring error for a 26 mm diameter circle at this speed is less than 4 μm. Tracking and contouring experiments are conducted for table feedrates as high as 10 m/min. Frequency domain analysis demonstrates that the feedforward controller achieves a bandwidth of 10 Hz without phase distortion. In a direct comparison of accuracy, the machining errors in specimens produced by the experimental controller were up to 20 times smaller than the errors in specimens machined by an industrial CNC.

Analysis of the Electro-Mechanical Responses of the Piezoelectric Motor Based on Finite Element Method

2014 ◽  
Vol 697 ◽  
pp. 181-186
Author(s):  
Zi Lei Wang ◽  
Tian De Qiu
Keyword(s):  
Finite Element ◽  
Coupling Effect ◽  
Complex Stress ◽  
Piezoelectric Resonator ◽  
Element Analysis ◽  
Mechanical Coupling ◽  
Mechanical Responses ◽  
Stress Boundary Condition ◽  
Piezoelectric Field ◽  
Stress Boundary

The piezoelectric field and structure field of piezoelectric resonator of ultrasonic motor are intercoupling. It is difficult to obtain the solution under some circumstances because of the complex stress boundary condition and the influence of coupling effect. An electro-mechanical coupling finite-element dynamic equation is established on the basis of the Hamilton’s Principle about piezoceramic and elastomer. The equation is decoupled through the shock excitation of the piezoelectric resonator and the piezoelectricity element and material provided by finite-element analysis. As a result, an admittance curve as well as the distribution status of the nodal DOF is obtained, which provides an effective method to solve electro-mechanical coupling problems.

Influence of Milling Parameters on Surface Residual Stresses of 7050-T7451 Aluminum Alloy

2012 ◽  
Vol 723 ◽  
pp. 208-213 ◽  
Author(s):  
Yi Wan ◽  
Chen Li ◽  
Zhan Qiang Liu ◽  
Shu Feng Sun
Keyword(s):  
Aluminum Alloy ◽  
Residual Stresses ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Orthogonal Direction ◽  
Mechanical Coupling ◽  
Surface Residual Stresses ◽  
Compressive Residual Stresses

Residual stresses generated in milling process affect the performance of machined components. Milling residual stresses correlate closely with the cutting parameters. In this paper, the generation and distribution of surface residual stresses in milling of aluminum alloy 7050-T7451 was investigated. The cutting speed changes from 300m/min to 3000m/min. In the experiments, the residual stresses on the surface of specimen are detected by X-ray diffraction technique. The result shows that compressive residual stresses are generated when cutting speed is under 500 m/min. In feed and its orthogonal direction, the effect of cutting speed and feed rate on residual stresses is similar. The formation of the residual stresses can be explained by thermo-mechanical coupling effects.

Microtexture Generation Using Controlled Chatter Machining in Ultraprecision Diamond Turning

2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Syed Adnan Ahmed ◽  
Jeong Hoon Ko ◽  
Sathyan Subbiah ◽  
Swee Hock Yeo
Keyword(s):  
Cutting Tool ◽  
Cutting Speed ◽  
Diamond Turning ◽  
Diamond Cutting ◽  
Machined Surface ◽  
Excited Vibration ◽  
Mass And Heat Transfer ◽  
Tool Shank ◽  
Diamond Cutting Tool

This paper describes a new method of microtexture generation in precision machining through self-excited vibrations of a diamond cutting tool. Conventionally, a cutting tool vibration or chatter is detrimental to the quality of the machined surface. In this study, an attempt is made to use the cutting tool's self-excited vibration during a cutting beneficially to generate microtextures. This approach is named as “controlled chatter machining (CCM).” Modal analysis is first performed to study the dynamic behavior of the cutting tool. Turning processes are then conducted by varying the tool holder length as a means to control vibration. The experimental results indicate that the self-excited diamond cutting tool can generate microtextures of various shapes, which depend on the cutting tool shank, cutting speed, feed, and cutting depth. The potential application of this proposed technique is to create microtextures in microchannels and microcavities to be used in mass and heat transfer applications.

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